Make App.all public

[Marc Knaup]

We'd like to do what #21 suggests directly in our app by simply checking which apps are installed.

Unfortunately the following won't work because .all isn't public:

let apps = App.all.filter(Karte.isInstalled)
if apps.count == 1 { … }

[Marc Knaup]

Btw, writing your own .all isn't event needed. You can simply use the CaseIterable protocol on the enum.

[Kilian Koeltzsch]

Ah, good point 👍 CaseIterable wasn't around yet when first writing this code.

[Kilian Koeltzsch]

fixed with 8a41fe4